public class YW_QuackCounter implements YW_Quackable {
	YW_Quackable duck;
	static int numberOfQuacks;
  
	public YW_QuackCounter (YW_Quackable duck) {
		this.duck = duck;
	}
  
	public void quack() {
		duck.quack();
		numberOfQuacks++;
	}
 
	public static int getQuacks() {
		return numberOfQuacks;
	}
}
